Drainage Analysis

What is drainage analysis?

Drainage analysis investigates the present geometries of river sysystems and what this can tell us about past changes in river networks. In resource exploration, and much of my research, this is used as part of the broader field of source-to-sink analysis.

Drainage analysis concepts and methodologies date back to the 1940s - 1960s and the work of geomorphologists looking for the causes of patterns in natural systems.

My research interests

With the first generation of my palaeogeophy maps in 1997, which were based on the Chicago method of Fred Ziegler (Ziegler et al., 1985), there was one missing element which was the reconstruction of palaeorivers. For my post-doc at Reading this was a problem, because the challenge I had was to use palaeogeography and palaeoclimate modelling to model potential placer deposits, and this needed an explicit definitions of the rivers of southern Africa.

Roll forward 25 years and presentations for Finding Petroleum (2013, 2015), and you can see how this was then applied to exploration, with a methodology to investigate changes in river systems (drainage analysis), the link between landscapes, erosion and tectonics (landscape analysis) and then converting this to past reconstructions of the rivers themselves, their drainage basin geometries and outfall points. This work was published as part of my 2004 paper with Paul Valdes, which focussed on how the resulting landscape maps (paleoDEMs) could be used for boundary condistions in coupled ocean-atmosphere climate models.

My research in this area continues to be dominated by how we can reconstruct past river systems, as the pathways for sediment transport. Drainage analysis forms only one part of this source-to-sink workflow, which also includes the application of climate models to examine weathering and sediment composition and flux, which has direct implications for resource exploration, but also an understanding of how modern rivers may respond to climatic and landscape changes.